LABORATORY INVESTIGATIONS IN SUPPORT OF CARBON DIOXIDE-LIMESTONE SEQUESTRATION IN THE OCEAN

In the first half of the second contractual year the High Pressure Flow Reactor (HPFR) was fully designed. Most components have been ordered, and assembly of the flow reactor has been started. Also, the High Pressure Batch Reactor (HPBR) was redesigned for more efficient operation and observation of the emulsion of liquid or supercritical CO{sub 2} dispersed in water stabilized by pulverized limestone and other particles. In this period we firmly established that when about equal volumes of liquid CO{sub 2} and a slurry of pulverized limestone (CaCO{sub 3}) in de-ionized or artificial seawater (3.5% NaCl solution in de-ionized water) are thoroughly mixed, a macro-emulsion ensues consisting of liquid CO{sub 2} droplets coated with a sheath of CaCO{sub 3} particles dispersed in water. We call the coated CO{sub 2} droplets globules, and the macro-emulsion a globulsion. Depending on the degree of mixing (rotational speed of the magnetic stir bar) and the size of the CaCO{sub 3} particles, the globules float on top of the water column, are suspended in it, or sink to the bottom of the water column. With CO{sub 2} droplet diameter in the 100-200 {micro}m range, and CaCO{sub 3} particles in the 6-20 {micro}m range, most of the globules sink to the bottom. The formation of sinking globules is desirable for ocean sequestration of CO{sub 2}. The properties and stability of the globules will be further investigated in the HPFR in the second contractual year. It has also been demonstrated that flyash can be substituted for pulverized limestone to obtain a stable globulsion of CO{sub 2}-in-water